OREGON CAVES The Underworld of Oregon Caves

Bacon
A thin sheet of calcite drapery having alternating dark and light bands which give it the appearance of a strip of bacon. The dark, reddish hands are usually caused by an iron oxide stain.

Bedding plane
The stratification or meeting place of two different layers ot sedimentary rock.

Blade
A calcite sheet originally deposited in a crack, then later exposed.

Breakdown
Heaps of rubble on a cavern floor caused by the collapse of walls or ceiling.

Calcium bicarbonate
An unstable compound occurring when carbonic acid contacts calcium carbonate.

Calcium carbonate
A mineral with the chemical formula CaCO₃.

Calcite
A crystalline form of calcium carbonate.

Carbonic acid
A weak acid occurring as a liquid, having the formula H₂CO₃, a mixture of carbon dioxide and water.

Clastic dike
A dike made up of fragments of pre-existing rocks.

Column
A speleothem formed when a stalactite and a stalagmite meet.

Deposit
A natural occurrence of mineral material, such as an iron ore deposit; or in the vocabulary of the speleologist, any cave formation originating from deposition.

Drapery
Hanging speleothem in the form of a curtain or drape.

Dripstone
A calcite deposit left by dripping water.

Flowstone
A calcite deposit left by flowing water along a cave wall or floor.

Fracture
A break in rock.

Gallery
An underground passage.

Ground water
Water within the earth, such as feeds wells.

Helictite
A variant form of stalactite which does not hang vertically or which has side growths resembling twisted roots.

Joint
A crack, which in limestone forms at an angle to a bedding plane. A series of joints often intersect each other in a four-sided pattern.

Limestone
A rock consisting chiefly of calcium carbonate, usually an accumulation of organic remains such as shells.

Marble
Limestone crystallized by metamorphism.

Metamorphose
To change into a different form, such as changing sedimentary rock (limestone) into a metamorphic rock (marble).

Moonmilk
A rare form of hydromagnesite or calcium carbonate which is semisolid.

Phreatic zone
The region, below the water table, in which rock is saturated with water.

Popcorn
Nodules of mineral deposits formed in such a way as to resemble popcorn.

Rimstone
A calcite deposit around the edge of a pool of water.

Sedimentary rock
Formed from deposits of sediments or from fragments of other minerals.

Shale
A sedimentary rock formed from deposits of clay or silt.

Solution
The process by which a substance is chemically combined with a liquid. Also, the state of being chemically so combined.

Soda straw
A small, hollow stalactite inside which drops of water descend.

Speleogen
A cave feature produced by solution of base rock.

Speleologist
One who makes a scientific study of caves.

Speleology
The scientific study of caves in all their aspects.

Speleothem
A cave feature produced by deposition of mineral

Spelunker
One who explores caves as a sportsman or amateur speleologist.

Stalactite
A calcite speleothem which grows downward, icicle-fashion, as a result of deposition by dripping water.

Stalagmite
A calcite speleothem which grows upward fromms a cave floor as a result of deposition by dripping water.

Vadose zone
The region lying between the surface of the earth and the water table. Water which seeps or flows through this region under the pull of gravity is called vadose water.

Water table
The meeting place of the phreatic and vadose zones. Below it, the rock is saturated with water; above it, water under the pull of gravity is continuously flowing downward.